URI Biological Oceanographers Study the
Predator-Prey Relationship between
Sand Shrimp and Flounder
Narragansett, R.I .– December 13, 2002 — While the stock of winter flounder, as a whole, is recovering from overexploitation, the populations in Narragansett Bay, Rhode Island, and Niantic River, Connecticut, remain depleted. Elevated water temperature seems to be the culprit, elevating the metabolism and consumption rate of predators that feast on the juvenile flounder. One predator that seems to be making a negative impact on the survival of flounder is the sand shrimp.
URI Graduate School of Oceanography (GSO) professor Jeremy Collie has received a $40,000 grant from the National Oceanographic and Atmospheric Administration (NOAA) to study the effects of water temperature on predator-prey interaction in Narragansett Bay and the Niantic River and determine why the stock of winter flounder continues to decline. Working with Collie on this project is GSO doctoral candidate David Taylor.
The common sand shrimp lives in the Atlantic waters from Newfoundland to Florida and is an important component of estuarine systems, serving as both predator and prey. Elevated winter water temperature possibly increases the number of sand shrimp simply because warmer temperatures allow greater numbers to survive the winter.
Another factor concerns the migratory pattern of the sand shrimp, which return to the shallow waters of the bay in late spring. Previously, juvenile flounder were able to grow to a body size that would prevent them from becoming a significant prey item for sand shrimp. With water temperatures, sand shrimp are moving into shallow waters earlier, while juvenile flounder are still vulnerable. In addition, increased water temperature could directly influence the physiology of sand shrimp by enhancing metabolic activity and thus increasing their predation of juvenile winter flounder.
“Investigating the effects of changes in temperature on population dynamics is increasingly important given the anticipated effects of global warming on marine and estuarine systems,” said Taylor. “Additionally, research identifying the influence of climatic variability on predator-prey relationships is critical for predicting the effects of changes in water quality on food web dynamics and the ability of juvenile flatfish to grow into adults.”
The data generated from this research will be made available to numerous organizations, including the National Marine Fisheries Service, state agencies, and utility companies.
The URI Graduate School of Oceanography is one of the countrys largest marine science education programs, and one of the worlds foremost marine research institutions. Founded in 1961 in Narragansett, RI, GSO serves a community of scientists who are researching the causes of and solutions to such problems as acid rain, harmful algal blooms, global warming, air and water pollution, oil spills, overfishing, and coastal erosion. GSO is home to the Coastal Institute, the Coastal Resources Center, Rhode Island Sea Grant, the Institute for Archaeological Oceanography, and the National Sea Grant Library.